Evolution of Sexual Dimorphism
Female (left) and male (right) flowering willow catkins. Male catkins abundant in pollen (bottom right).
Female (top) and male (bottom) guppies.
Female (left) and male (right) adult jumping spiders.
I am a Postdoctoral Research Fellow in Judith Mank's lab at The University of British Columbia. Through my research, I am interested in understanding the selective forces and mechanisms underlying the evolution of sexually dimorphic traits. My work revolves around the study of sex chromosomes and of differentially expressed genes between males and females.
Research and travel grants
Key conference and seminar contributions
Oral Presentation, The Evolution of Cooperation and Conflict Symposium, Uppsala Sweden
Speaker at the London Soapbox Science event
The evolution of sexual dimorphism
Despite sharing the majority of their genome, males and females of the same species often show a wealth of phenotypic differences, affecting morphology, physiology, behavior and life history, among other traits. I am broadly interested in how sex-specific evolutionary pressures shape distinct male and female phenotypes. In some species, the two sexes differ by their sex chromosomes, and sex-limited (Y or W) genes partly explain the observed sexual dimorphism. To a large extent, however, sex differences are encoded by genes that are shared between males and females but that are expressed differently in the two sexes (sex-biased genes). In my research, I integrate genomic and transcriptomic data to explore the evolution of sex chromosomes and of sex-biased gene expression and their role in sexual dimorphism.
Sex-biased gene expression
Many sexually dimorphic characteristics have been studied in relation to differential regulation of genes present in both sexes, referred to as sex-biased gene expression. Depending on the sex in which they are predominantly expressed, sex-biased genes can be divided into male-biased or female-biased, with genes showing similar expression between the sexes referred to as unbiased. Sex-biased genes are thought to evolve in response to conflicting sex-specific selection over optimal expression.
I use transcriptomic and bioinformatic tools to study the breadth of differential gene expression within populations and throughout development, and the mechanisms underpinning the evolution of sex-biased genes.
9. Darolti I, Wright AE, Mank JE (2020) Guppy Y chromosome integrity maintained by incomplete recombination suppression. Genome Biology and Evolution in press.
8. Furman BLS, Metzger DCH, Darolti I, Wright AE, Sandkam BA, Almeida P, Shu JJ, Mank JE (2020) Sex chromosome evolution: So many exceptions to the rules. Genome Biology and Evolution in press.
7. Darolti I, Wright AE, Sandkam BA, Morris J, Bloch NI, Farré M, Fuller RC, Bourne GR, Larkin DM, Breden F, Mank JE (2019) Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers. Proceedings of the National Academy of Sciences 116:19031.
6. Farré M, Li Q, Darolti I, Zhou Y, Damas J, Proskuryakova AA, Kulemzina AI, Chemnick LG, Kim J, Ryder OA, Ma J, Graphodatsky AS, Zhang G, Larkin DM, Lewin HA (2019) An integrated chromosome-scale genome assembly of the Masai giraffe (Giraffa camelopardalis tippelskirchi). GigaScience 8:giz090.
5. Wright AE, Darolti I, Bloch NI, Oostra V, Sandkam BA, Buechel SD, Kolm N, Breden F, Vicoso B, Mank JE (2019) On the power to detect rare recombination events. Proceedings of the National Academy of Sciences 116:12607.
4. Morris J, Darolti I, Bloch NI, Wright AE, Mank JE (2018) Shared and species-specific patterns of nascent Y chromosome evolution in two guppy species. Genes 9:238.
3. Fox G, Darolti I, Hibbitt JD, Preziosi RF, Fitzpatrick JL, Rowntree JK (2018) Bespoke markers for ex-situ conservation: application, analysis and challenges in the assessment of a population of endangered undulate rays. Journal of Zoo and Aquarium Research 6:50-56.
2. Darolti I, Wright AE, Pucholt P, Berlin S, Mank JE (2018) Slow evolution of sex-biased genes in the reproductive tissue of the dioecious plant S. viminalis. Molecular Ecology 27:694–708.
1. Wright AE, Darolti I, Bloch NI, Oostra V, Sandkam BA, Buechel SD, Kolm N, Breden F, Vicoso B, Mank JE (2017) Convergent recombination suppression suggests a role of sexual conflict in guppy sex chromosome formation. Nature Communications 8:14251.